The 6C4 triode valve was specified as both an amplifier and an RF power valve. In the latter role it would deliver 5.5 Watts in class C operation. With a very small envelope volume, this would make it ideal for hand portable equipment. In larger apparatus it could deliver enough drive power for much larger PA's.
The 6C4 electrodes when put into pairs in the same envelope become the 12AU7.
The Small electrode system seen end on. The rod at the right supports the getter holder.
The folded anode is stitched on one side. The control grid has heat radiating fin at the top. This valve was made in England.
The side rod also provides support for the mica discs.
The thin glass tube envelope is 18 mm in diameter and, excluding the B7G base pins, is 47 mm tall.
